@RockyMountainBicycles can you comment on system drag? Is it like a Bosch...or a Shimano in terms of powered-off drag? I know the jocky wheel probably adds a bit, but exclusive of that, how is your system?
And lastly, is this system seen in any of the Evox brand bikes with the jocky wheel implementation?

Calling it now. A 1x ring that can slide left and right by 1-2mm on some sort of spindle sleeve or spider flex plate. Corrects for chainline issues with 13 gears (or even 12). Should be easy to do.
SRAM, put my check in the mail if you didn't already think of this.

Lightly used, super clean 2015 Salsa El Mariachi 3 in Stormy Blue colorway.
29errrrrr!
Size small.
Chromoly steel frame.
Some frame/component scratches from low-speed tipovers, but never crashed hard.
100mm Rock Shox Recon Gold fork. No scratches on stanchions!
Brakes workin' great!
Double-ring crank version (Salsa offered a triple as well).
Set up tubeless with Maxxis Ardents (2.35 I believe). Front sealant changed recently. Will throw in a small bottle of sealant for the rear tire, but I think it's still good.
Will throw in stock saddle as well.
Makes a great entry-level mountain bike, bikepackin' rig, or high-speed gravel grinder. Convert to drop bars, even! I almost did, and it seemed like the stack/reach would be okay. Steer tube is uncut.
Has swinging alternator dropouts so you can run it single-speed easily, or convert to belt drive with the right adapter plate from Salsa.
I am 5'7" and you probably won't want to be any taller. I think you could be down to like 5'2" maybe? My wife is 5' and she can ride it although the big wheels are kind of excessive for her.
Salsa product page: http://salsacycles.com/bikes/archive/2015_el_mariachi_3
Shipping info: Price in ad is for the bike professionally boxed (i.e. not by me!) and shipped to anywhere in the lower 48!!